Because subsurface burial of industrial chemicals has been a common method of waste disposal, a mathematical model describing the simultaneous transfer of heat, moisture, and chemicals in unsaturated and saturated soils was developed. By subdividing the soil into layers, heat, mass, and moisture balances can be constructed for each layer transforming a continuous nonlinear model into a model that is more easily solved. This model has been used to examine the transport of PCBs in soils with different adsorptive capacitites. The design of incinerators for PCBs has been analyzed to determine the conditions necessary for destruction without formation of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs). Formation of PCDFs and PCDDs is eliminated by maintaining in the combustion chamber sufficient temperatures, residence times, turbulence, and oxidizing conditions that are similar to the design features of an isothermal plug flow reactor. The study of the mobilization of arsenic by industrial processes focussed on coal combustion for electric power production and new uses of coal for liquefaction and gasification. Arsenic is vaporized during combustion and deposited largely on submicron particles. Much of this material passes through most air pollution control equipment. Analyzing data for partitioning of arsenic in liquefaction and gasification indicated that in liquefaction the potential for formation of organometallic compounds of arsenic is high. For gasification the atmospheric release of arsenic deposited on submicron particles is the most probable route of environmental entry.